fmmv

In case its not obvious you can replace juat the ignition switch, ie the electrical bit, and keep the existing lock.

I have had a similar experience to the OP's. Our street is steep downhill, then level to a T junction where you have to climb up reasonably steeply again. So initially you need next to no throttle, till the T. Then the engine has to actually work, and like you, we had initial hesitation, then some smoke and splutter and after that all seemed to be OK, not even every time. This is on a 300. I admit I treated it as "it's OK now , let's just pretend that didn't happen for now" and put it on the todo list. For separate reasons completely I swapped the turbo (went VNT) and the problem went away, and has been gone for years. I can't say for sure therefore what it was, I may have inadvertently fixed it while swapping turbos, or it may have been the turbo itself. When I looked at the old turbo having got it off, the compressor vanes had been rubbing the scroll, just slightly ( I knew it had had a good innings) . So maybe it didn't spin properly till the oil pressure had lifted it clear of the scroll, and it could spin freely, and that was my hesitation clearing. But that's a maybe, I have no definite idea what was causing it. Your smoke is black so that suggests over fuelling or shortage of air for some reason. Or maybe it could be an injection pump issue, something sticking in there. I think there is a device within the FIP that gives it full fuel for cold start, hence the puff of black smoke on startup - maybe that is sticking. If you have a boost gauge or could temporarily plumb one you could see if the boost when it's cold matches what it is when you do the same journey when it's running Ok, so that would help eliminate the turbo side. Can you get it to 'cough' just stationery when cold or does it have to be moving? Might be worth taking the diaphragm off the top of the pump and making sure the pin that bears against the boost pin can move easily (mark position of diaphragm and return to same) as they are known to stick, it's only 4 screws. Just another thought... does this only happen when the weather is cold?

Those clips do seem to have very sharp corners on them, they may be better for the hoses but they can do you some damage if you reach past them in a confined space.

Wow, talk about right place, right time

What @FridgeFreezer said. To elaborate a bit the earth point on the top of the bulkhead seems a prime candidate, also another on the RH side of the transfer case. Assuming pre-Puma. If you cast around internetly you will be able to download a manual of electrical diagrams and also the Defender Electrical Library. The points named in the wiring manual are often pictured in the Electrical Library so you can see exactly where they are. Lots of good reading material in there (for insomniacs).

Presuming there is no G valve or similar involved? Incidentally , fluid darkens as it absorbs water, so it doesn't necessarily mean the seals are going. A fluid change is a good initial idea, might even be trapped air somewhere.

I must admit I"m struggling to see how wheel bearings can affect drums Discs, yes, but drums no. Since the fluid is effectively incompressible I think I would suspect the beginning of master cylinder failure, where the seals aren't quite sealing initially but then do as pressure builds. But I admit that's a pure guess.

Or Yorkshire fittings have swaged ends, you can just leave one end empty at each end of the pipe.

I think you are referring to an injector, ie fitting in middle top. That has to be innocent. The rusty bolt head is a cylinder head bolt, it could conceivably be leaking up that. Or it could be the core plug visible in the left of the bottom picture. Or about 20 other things. As @Eightpot advises it needs the head off and investigating. Or if you want to try to diagnose it first try getting the cooling system pressure tested.

I think the pumas have progressive variable rate rear springs Might be worth looking into.

JLR should be ashamed. Ok, these are not new vehicles. But by contrast I have a 2009 Ford and it has just been recalled for a problem with airbags. It was off the road when I got the recall letter so I was bit tardy arranging to take it in But just after, Ford wrote to me again, obviously news of it being done hadn't reached them. So clearly they are trying hard to do the right thing. These problems do happen, mistakes are made, things emerge later. Credit to Ford for doing the right thing. JLR seems to just hope its OK and cover it up. They would do well to note what happened when the Post Office tried that.

If you have an older driver with a clean record added as a named driver that can sometimes substantially reduce premiums.

Don't forget Land Rovers like to mark their territory. Leaks may be from any or even all of the above points, don't assume there is only one.

I think prime suspect has to be earth connections, might be ones to the lights or esp if it afflicts all, the earthing points, eg on the transfer box RH side, bulkhead etc.

I have used the Foliatec 2 pack caliper paint successfully, been on around 7 years with just the odd chip.

I think its well worth painting new calipers before they turn into a rusty mess. If ever "a stitch in time.." was true....

If they've done a proper job, and it sounds like they have, it seems very reasonable. You have just given it a good test with your Greek trip @Peaklander.

May I ask who did it, and was it satisfactory?

Great news! So pleased to hear that

I think the OP specifically said he didn't plan to increase fuelling beyond stock. It sounds like a boost leak, maybe blocked fuel filter or struggling fuel pump or mis-timed pump or camshaft.

That was the perfect spanner(wrench), and, well done, you have displayed the ingenuity and resourcefulness needed to keep your Defender on the road(highway).

For the record, the fan bearing on the timing cover is I think is Koyo 885802 RS ( I have made a note of it from somewhere else) and can be replaced by a John Deere waterpump bearing part number JD9257 superseded by JD9448 ( both of which needs a bit of the shaft cut off). I also have a note of SKF 374056B against this bearing.

Its worth looking at because the timing cover bearing is difficult to source and difficult to replace, or you have to replace the whole cover. Yes 300 tdi are very vulnerable to low coolant, probably its biggest Achilles heel.

I have dim memory of someone posting that you could use a shorter belt, and bypass the fan pulley thus removing the bearing wear on the timing cover, but I can't find it just now.

You could probably make a spanner if you have some 3mm plate, it just needs 2 tightish fitting jaws and a handle long enough to hit with a hammer. They normally unscrew easily after a good smite.